1. Field of the Invention
The present invention relates to an indicator, and especially to a flow indicator used in a pumping pipe line for a submerged pump having a filtering-cotton filter, which is a flow indicator for showing blocking of filter cotton.
2. Description of the Prior Art
A simple water spraying system used in a pond mainly has a spraying head of which a pipe line is connected to a submerged pump for water spraying of the spraying head. But for keeping long life of use of the submerged pump, the submerged pump must be connected to a filter to filter out the impurities in the water.
In a filter of the kind often seen, filter cotton is given to provide a function of filtering, while after using for a long time, the filter cotton will be blocked, hence water pressure in pumping of the submerged pump will be lowered, but a user is unable to be aware of this and is unable to change the filter cotton or clean the filter in time, this is a problem resided in the conventional filters, and improvement is wanted.